LOD-AM Triplestore

Docker deployment of the LOD-AM triplestore based on secoresearch/fuseki (maintained by SemanticComputing) with nickfedor/watchtower for automatic container updates.

Note: This configuration is aligned with the SemanticComputing/fuseki-docker image approach.

Quick Start

1. Create local directories and set permissions:

   mkdir -p fuseki-data fuseki-config
   # Fuseki runs as UID 9008 - grant write access
   sudo chown -R 9008:9008 fuseki-data/ fuseki-config/

2. Set environment variables in your ~/.bashrc:

   # Fuseki
   export FUSEKI_ADMIN_PASSWORD="your_secure_password"
   export FUSEKI_JAVA_OPTS="-Xmx4G"  # Optional: JVM memory settings
   
   # Watchtower Email Notifications
   export WATCHTOWER_NOTIFICATIONS=email
   export WATCHTOWER_NOTIFICATION_EMAIL_FROM="watchtower@yourdomain.com"
   export WATCHTOWER_NOTIFICATION_EMAIL_TO="admin@yourdomain.com"
   export WATCHTOWER_NOTIFICATION_EMAIL_SERVER="smtp.yourdomain.com"
   export WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT=587
   export WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER="smtp_user"
   export WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD="smtp_password"
   export WATCHTOWER_NOTIFICATION_EMAIL_DELAY=2  # Optional: default is 2

3. Source your .bashrc:

   source ~/.bashrc

4. Start the services:

   sudo -E docker compose up -d

5. Access Fuseki:

   • Web UI: http://localhost:3030
   • SPARQL endpoint: http://localhost:3030/LOD-AM/sparql

Configuration

• Persistent storage: Fuseki data is stored in ./fuseki-data/ (bind mount to /fuseki-base/databases)
• Custom configs: Mount your assembler.ttl or shiro.ini in ./fuseki-config/ (bind mount to /fuseki-base/configuration)
• Watchtower: Monitors and updates containers automatically, sends email notifications on updates
• Reasoning: Currently disabled - AFO and CIDOC CRM will be implemented directly without inference mappings

Fuseki Configuration File

The repository includes a minimal fuseki-config/assembler.ttl that:

• Uses TDB1 dataset type (tdb:DatasetTDB) compatible with secoresearch/fuseki image
• Stores data at /fuseki-base/databases/tdb
• Enables Graph Store Protocol (GSP) for data upload/edit in the UI
• Excludes reasoning (no RDFS/OWL inference)

Important: When using bind mounts for configuration, manually edit assembler.ttl to enable endpoints rather than using environment variables (due to permission restrictions).

To apply configuration changes:

sudo -E docker compose down && sudo -E docker compose up -d

Environment Variables

Fuseki

Variable	Required	Default	Description
FUSEKI_ADMIN_PASSWORD	Yes	-	Admin password for Fuseki
FUSEKI_JAVA_OPTS	No	-Xmx4G	JVM options for memory tuning

Watchtower

Variable	Required	Default	Description
WATCHTOWER_NOTIFICATIONS	No	email	Notification method
WATCHTOWER_NOTIFICATION_EMAIL_FROM	Yes	-	Sender email address
WATCHTOWER_NOTIFICATION_EMAIL_TO	Yes	-	Recipient email address
WATCHTOWER_NOTIFICATION_EMAIL_SERVER	Yes	-	SMTP server hostname
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT	Yes	-	SMTP server port
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER	No	-	SMTP username
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD	Yes	-	SMTP password
WATCHTOWER_NOTIFICATION_EMAIL_DELAY	No	2	Delay between notifications in seconds

Architecture

• Fuseki: Triplestore server on port 3030
• Watchtower: Monitors and updates containers automatically
• Network: Isolated lod-am-network for internal communication

Troubleshooting

Environment variables not set

If you see The "VARIABLE" variable is not set, use sudo -E to preserve your environment:

sudo -E docker compose up -d

Or configure sudo to keep specific variables:

echo 'Defaults env_keep += "FUSEKI_ADMIN_PASSWORD FUSEKI_JAVA_OPTS WATCHTOWER_*"' | sudo tee /etc/sudoers.d/env_keep

Permission denied errors

The secoresearch/fuseki container runs as UID 9008. If you see Not writable errors, ensure both directories have correct ownership:

sudo chown -R 9008:9008 fuseki-data/ fuseki-config/